The role of high temperature superconductivity in energy related fields is widely accepted. A serious limitation to the wide spread use of these materials is the cost and complexity of producing these materials in a form suitable for large scale uses. It is already known that the critical current densities in the high temperature cuprate semiconductor (HiTc) materials are very high in single crystal epitaxial films, that grain boundaries are Josephson coupled and hence limit the critical current densities in polycrystalline materials and the critical current densities across grain boundary is a function of the misorientation angles of two grains adjoining the boundary.
As stated above, the critical current density of the cuprate superconductors is limited by grain boundaries. The critical current density in a magnetic field of a low angle grain boundary is further limited by the motion of Abrikosov (A) vortices, Josephson (J) vortices, or Abrikosov-Josephson (A-J) vortices. These vortices experience a Lorentz force when a combination of current flow and magnetic field are present and move along the grain boundary. Movement of the vortices causes a decrease in the critical current.
Current density is also affected by the misorientation angle between two adjoining grains; the larger the misorientation angle between two adjoining grains the smaller the current density. Thus a great deal of effort has been expended around the world to develop manufacturing processes that minimize the misorientation angle between two grains. Even in these low angle boundaries the critical current is not as high as desirable. Accordingly a method is desired to enhance the critical current density. A method is desired that will enhance the critical current density using fundamental properties of the materials. A method is further desired that will enhance the critical current density using wave function symmetry. An object of the present invention is to use spatially and temporally bound vortices formed in a d-wave superconductor to impede the motion of Abrikosov and Josephson vortices. A method is also desired to fabricate cuprate superconducting tapes on single crystal metallic substrates.